Wednesday, March 16, 2011

Never forget: Elephants do have good memories and the eldest are best at making crucial decisions because they've experienced similar peril before

Elephants actually do have the long memories they are credited with – especially when it comes to danger, scientists say.

They found that older elephants are the best at making crucial decisions about predators because they’ve experienced similar peril before.

A study of African elephants found group elders were better at making crucial decisions about predators because of their earlier experience.

When families were played male or female lion roars from a loudspeaker - simulating their presence - those with older matriarchs correctly focused their defensive reactions on male lions that are the more adept killers.

Dr Karen McComb, of the University of Sussex, and colleagues said the ability to make this subtle distinction highlights the importance of age in leadership and the advantage of longevity in large-brained, social mammals.

Elephants live in multi-generational families of up to 12 members that feed, rest, and move as one unit. Together they defend each other, search for food and care for offspring.

During 72 playbacks of lion roars among 39 family groups in Boseli National Park in Kenya over more than two years, the oldest matriarchs listened intently for longer periods and led their group into more defensive positions when it was a male roar.

The researchers said: 'Our work provides the first direct experimental evidence that older matriarchs are in fact able to make better decisions when faced with ecological challenges in this case, the presence of dangerous predators.'

Recent research has suggested prey species with large brains relative to their body size may be better at evading predators because they can more effectively adjust their behavioural responses to specific encounters.

The researchers say their findings, published in Proceedings of the Royal Society B: 'Demonstrate how the accumulated knowledge of the oldest individuals may have an overriding influence on the effectiveness of anti-predator decisions made by the social group as a whole, and highlight the vital role of such individuals in natural populations.'

But poaching means the number of older matriarchs has fallen dramatically.